John B. Watson, after observing children in the field, was interested in finding support for his notion that the reaction of children, whenever they heard loud noises, was prompted by fear. Furthermore, he reasoned that this fear was innate or due to an unconditioned response. He felt that following the principles of classical conditioning, he could condition a child to fear another distinctive stimulus which normally would not be feared by a child.

The aim of Watson and Rayner was to condition phobias into an emotionally stable child.[1] They chose "Albert" for this study (at the age of about nine months) from a hospital.[2]

As the preliminary to the experiment, Little Albert was given a battery of baseline emotional tests: the infant was exposed, briefly and for the first time, to a white rabbit, a rat, a dog, a monkey, masks (with and without hair), cotton, wool, burning newspapers, and other stimuli. During the baseline, Little Albert showed no fear toward any of these items. Albert was then placed on a mattress on a table in the middle of a room. A white laboratory rat was placed near Albert and he was allowed to play with it. At this point, the child showed no fear of the rat. He began to reach out to the rat as it roamed around him. In later trials, Watson and Rayner made a loud sound behind Albert's back by striking a suspended steel bar with a hammer when the baby touched the rat. Little Albert responded to the noise by crying and showing fear. After several such pairings of the two stimuli, Albert was again presented with only the rat. Now, however, he became very distressed as the rat appeared in the room. He cried, turned away from the rat, and tried to move away. Apparently, the baby boy had associated the white rat (originally a neutral stimulus, now a conditioned stimulus) with the loud noise(an unconditioned stimulus) and was producing the fearful or emotional response of crying (originally the unconditioned response to the noise, now the conditioned response to the rat).

This experiment led to the following progression of results: First, the introduction of a loud sound (unconditioned stimulus) resulted in fear (unconditioned response)—a natural response.[3] Secondly, the introduction of a rat (neutral stimulus) paired with the loud sound (unconditioned stimulus) eventually resulted in fear (unconditioned response).[3] Finally, the successive introductions of only a rat (conditioned stimulus) resulted in fear (conditioned response). Therefore, learning was demonstrated.

Watson used the same kind of classical conditioning as Pavlov had used in his experiments with dogs.[4]

The experiment showed that Little Albert seemed to generalize his response to furry objects so that when Watson sent a non-white rabbit into the room seventeen days after the original experiment, Albert also became distressed. He showed similar reactions when presented with a furry dog, a seal-skin coat, and even when Watson appeared in front of him wearing a Santa Claus mask with white cotton balls as his beard. Albert, however, did not fear everything with hair; and there was some confusing results when pairing the noise with the rabbit and dog.[3]

Albert exhibited an approach and avoidance conflict with the objects presented to him at the age of 1 year and 21 days, his age at the conclusion of the experiment. Albert was then reportedly removed from the hospital.[5]

Watson had discussed (hypothetically) how to desensitize a human, but knew from the beginning of the study the possibility existed that there would not be time to do so with Albert. As Albert left the hospital on the day the last tests were made, no desensitizing ever took place, and it is possible that his fear responses continued post-experimentally.[6]

Following the conclusion of the experiment, Watson gave a series of weekend lectures describing the Little Albert study. One of these lectures was attended by Mary Cover Jones, which sparked her interest in pursuing graduate work in psychology. (She became known as the "Mother of Behavior Therapy" following a study she conducted on a three-year-old.)[7]

According to some textbooks, Albert's mother worked in the same building as Watson and didn't know the tests were being conducted. When she found out, she took Albert and moved away, letting no one know where they were going. A 2009 report, however, disputes that.[8]

The original report noted that the baby's mother was a wet nurse at the hospital. Because wet nurses were of low social status, and because she worked for the institution itself, she may have felt coerced and unable to turn down a request for her baby to be used in Watson's experiment. "Voluntary consent, as we understand the term today, was not possible to give or to withhold", they wrote. Presumably, most parents—if given a choice—would not allow their babies to participate in an experiment in which researchers plan to terrify them.[9]

In 2009, psychologists Hall P. Beck and Sharman Levinson published an article in which they claimed to have discovered the true identity of "Albert B."[8] After reviewing Watson's correspondence and publications, as well as research in public documents (such as the 1920 United States Census and state birth and death records), Beck argued that "Albert B." was a pseudonym for Douglas Merritte, the son of Arvilla Merritte, then a woman who appears to have been a wet nurse at the Harriet Lane Home.[8] Recent research has shown, however, that Douglas Merritte may not have been "Little Albert" (Digdon, N., Powell. R. A., & Harris, B., in press; Powell. R. A., Digdon, N., Harris, B. & Smithson, C., in press).

MacEwan University psychology researchers Russ Powell and Nancy Digdon found that Little Albert was most likely William Albert Barger. He had been born within a day of Merritte, was known by friends and family as "Albert" even though his given name was William, and his mother had also worked at the hospital where the experiment was conducted. In addition, his size and developmental condition much more closely matched the experiment's documentation of the subject baby's condition. [10] Through the use of a professional genealogist, the researchers learned Barger had died in 2007 at age 87 and identified one close living relative, a niece. In an interview, Barger's niece stated that she and her uncle had been quite close throughout his life, acknowledged Barger's antipathy toward dogs as a well-known fact that family members would tease him about (the researchers noted there was no way to determine whether or not this behavior was linked to Watson's experiment), and stated that she did not recall any other phobias. The researchers concluded that Barger was unaware of his role as an infant test subject.[11]

Albert was only about eight months old at the time of the first test. Because of his age, the experiment today would be considered unethical by the American Psychological Association's ethic code (see references). Since the experiment, and other later studies which pushed the boundaries of experimental ethics, legislation was passed to prevent unethical and potentially harmful experiments. Health Insurance Portability and Accountability Act of 1996, the Public Health Service Act, and new required education in using human research participants was put into place by the National Institutes of Health in 2000. In the early 1970s, following widely publicized cases of research abuse, The National Commission for the Protection of Human Subjects of Biomedical and Behavioral Research (NCPHS) was created to study issues surrounding the protection of humans in research. In 1979, the Commission issued a report entitled "Ethical Principles and Guidelines for the Protection of Human Subjects of Research" (commonly called the "Belmont Report"), which provided the ethical framework which federal regulations for the protection of human participants in research are currently based on.[12][13] Under the NCPHS standards set in the late 1970s, an experiment such as Watson's would not have been allowed.[14][15]

Albert's conditioned fear was never extinguished, because the program ended before systematic desensitization was administered. It is presumed, although he still must have displayed fear to many various stimuli after moving, he would likely have been desensitized by his natural environments later in life. Today's ethical guidelines would not permit this study to be carried out or replicated.[13][16]

A common belief about the experiment is that it was performed without the knowledge or consent by Albert's mother.[8] Recent investigation has shown this to be false.[8] However, though Albert's mother may have in fact given her consent, it is also reasonable to believe that she felt pressured by a number of factors to agree to let Albert participate in the experiment even if she did have reservations. It is known that Albert's mother worked as a wet nurse at Johns Hopkins University, where Watson was employed and the experiment took place. Also, as a wet nurse, Albert's mother would have been considered to have a low social status. Since little Albert's mother was asked by a famous psychologist and fellow Johns Hopkins employee, it is possible she agreed out of fear for the future of her job and pressure from individuals with higher social power. It would have been a further source of questionable ethics for this experiment which already has some other questionable ethical components.[9][17] Researchers today are required to obtain fully informed consent from participants, or—in the case of children—from their parents or guardians.

A detailed review of the original study and its subsequent interpretations by Ben Harris (1979)[18] stated:

Critical reading of Watson and Rayner's (1920) report reveals little evidence either that Albert developed a rat phobia or even that animals consistently evoked his fear (or anxiety) during Watson and Rayner's experiment.

It may be useful for modern learning theorists to see how the Albert study prompted subsequent research [...] but it seems time, finally, to place the Watson and Rayner data in the category of "interesting but uninterpretable" results.

It is difficult to be certain exactly what happened during the Little Albert Experiment since there is a lack of concrete evidence and scientific records. Though a video was taken during the experiment, some textbooks even interpret that differently. Different sources give contradicting information on the course of events that took place surrounding the Little Albert Experiment. Some of these events include what exactly the baby in the experiment was conditioned with, what he later had fears of, and what happened to the child after the experiment.[19]

It was found that most textbooks "suffer from inaccuracies of various degrees" while referring to Watson and Rayner's study. Texts often misrepresent, exaggerate, or minimize the range of Albert's post-conditioning fears.

^Note: It is now considered unethical to evoke reactions of fear in humans under laboratory circumstances, except when the participant has given informed consent to being purposely horrified as part of the experiment. The standards dictate that experiments should not cause the human participants to suffer unnecessary distress or to be in any way physically harmed. The welfare of the human participants must always be the paramount consideration in any form of research, and this is especially true with specially protected groups such as children.